Long-term outlook for volcanic activity in Long Valley caldera

The area of eastern California that includes the Long Valley Caldera and the
Mono-Inyo Craters volcanic chain has a long history of
geologic activity that includes both earthquakes and volcanic eruptions.
This activity is likely to continue long into the future. When measured in the
time-scale of a human lifetime, volcanic eruptions or destructive earthquakes
are infrequent events. How does this ongoing geologic activity affect those who
live in or visit this area of spectacular eastern Sierra scenery?

The best guide to the future behavior of a volcano or volcanic system is its
past behavior. Geological studies of Long Valley Caldera and the Mono-Inyo
Craters volcanic chain indicate that:

Future eruptions are more likely to occur somewhere along the Mono-Inyo Craters
volcanic chain than from the resurgent dome or south moat area within the
caldera.

In the absence of unrest (earthquake swarms, ground deformation, gas emissions,
and fumarole activity), the odds of an eruption occurring in any given year
along the chain are one in a few hundred (comparable to the odds for a great
[magnitude 8] earthquake along the San Andreas fault in coastal California).

Unrest can temporarily increase the odds of an eruption, depending on the
nature, intensity, and location of the unrest.

Future eruptions are likely to be explosive in style but small to moderate in
size (Click here for a note on eruption
sizes.) Effusive (non-explosive), Hawaiian style eruptions are also possible
but somewhat less likely.

The odds that a small eruption somewhere along the chain will have a significant
impact on any specified place along the chain are roughly one in a thousand in a
given year.

Larger eruptions are possible but less common (and thus less likely) than
smaller ones (true for most volcanoes).

Massive eruptions of the size that accompanied formation of Long Valley Caldera
760,000 years ago are extremely rare (none have occurred during the period of
written human history). Scientists see no evidence that an eruption of such
catastrophic proportions might be brewing beneath Long Valley caldera.

All but three of the 20 or so eruptions over the past 8,000 years at Long Valley
Caldera have been explosive in nature. Those three were of the effusive,
Hawaiian type (the Red Cones eruptions south of Mammoth Mountain about 8,000
year ago, the Negit Island eruption about 2,000 years ago, and the Paoha Island
eruption just 250 years ago). All have been small to moderate in scale. So what type of
eruptions can we expect at Long Valley Caldera?